class A:
    a = 10
    b = [5, 1, 3]
    # name 'a' is not define。除了 b 作为外部唯一可迭代对象传入，列表表达式不能反问外部变量
    # print([a * i for i in b])
    print([i for i in b])  # [5, 1, 3]


A()
